Vascular incisor and method

ABSTRACT

An improved vascular incisor and method for allowing a user to safely create an incision in a body lumen. The present invention provides an apparatus which can create an incision in a front wall of the ascending aorta while preventing the blade from creating an incision in surrounding body structures, such as the back wall of the ascending aorta. The incisor includes a surgical element such as a blade which is activated by an actuator. As the actuator is depressed, the blade is moved from a protected, retracted position to an exposed, deployed position. The exposed blade is pushed into a front wall of the ascending aorta to create an incision. As the actuator is depressed further, the blade is automatically moved to the retracted position to prevent the blade from incising the back wall of the aorta.

BACKGROUND OF THE INVENTION

[0001] The present invention is directed to methods and devices forsafely creating an incision through a wall of a patient's blood vessel.Such devices and methods are useful for performing various procedures ona patient's vascular system and heart such as the procedures describedin U.S. Pat. Nos. 5,584,803 and 5,682,906 which describe coronary artybypass grafting (CABG) and valve procedures, respectively.

[0002] Prior to occluding the ascending aorta and maintainingcirculation of oxygenated blood, an incision must be made in theascending aorta and a cannula inserted for return of blood to thepatient. However, conventional methods suffer from potentially seriousdrawbacks. Conventional surgical techniques use a scalpel or knife tocreate an incision in the front wall of the ascending aorta prior to theinsertion of the cannula into the aorta. Such scalpels have thepotential to injure surrounding body structures. Additionally, in closedchest procedures, it is difficult and time consuming for the surgeon toseparately manipulate both the scalpel and cannula.

[0003] Accordingly, there is a need for an incision method and devicewhich can quickly and easily create an incision within the front wall ofthe ascending aorta through a small incision in the chest rather than afull sternotomy.

SUMMARY OF THE INVENTION

[0004] The present invention provides an improved vascular incisor, andcannula assembly and method for allowing a user to safely create anincision and insert a cannula in a body lumen. More specifically, thepresent invention provides an apparatus which can create an incision ina wall of the ascending aorta and insert a cannula in a fast andconvenient single step process. The present invention includes a cannulaand an incisor positionable within the cannula. The incisor has a bladewhich is moved by an actuator such as a trigger or a plunger. As theactuator is depressed, the blade is moved from a protected, retractedposition to an exposed, deployed position. The exposed blade is pushedinto a front wall of the ascending aorta to create an incision. As theplunger is depressed further, the blade is automatically moved to theretracted position to prevent the blade from contacting other bodystructures such as the back wall of the aorta. As the incisor is pushedthrough the incision, the cannula can be simultaneously inserted throughthe incision in a single step process.

[0005] In a first aspect, the present invention provides an incisor forcreating a vascular incision. In one embodiment, the incisor has a rodwhich is movable relative to a body. A surgical element, such as ablade, is disposed at a distal end of the rod. A plunger having at leastone finger engages a proximal end of the rod. When the plunger is movedfrom an undepressed position to a depressed position the rod andsurgical element are advanced from the retracted position to thedeployed position. The finger engages a ramp so that the fingersdisengages from the proximal end of the rod, and the surgical element ismoves back to the retracted position. In a specific configuration theincisor has a return spring to bias the plunger to the undepressedposition. As the plunger is biased back to the undepressed position, theplunger fingers pass by the proximal surface of the push rod and theresilient spring force contained in the flexed plunger fingers biasesthe finger radially inward into the initial position and into engagement(or near engagement) with the proximal end of the push rod. At thisposition, the plunger and push rod are positioned for repeat actuationof the blade.

[0006] In another embodiment, the incisor includes a housing and amovable push rod. The push rod is biased toward a retracted position.Actuation of a trigger pin over a ramp moves the push rod and a surgicalelement from the retracted position towards a deployed position. Whenthe trigger pin reaches a top of the ramp, the trigger pin disengagesfrom the push rod and allows the surgical element and the push rod toreturn to the retracted position. In some embodiments, the trigger pinis coupled to an actuator, such as a trigger or a plunger. The actuatoris actuated in the distal direction to move the trigger pin distallyover the ramp. In one configuration, the actuator is biased towards aninitial position so that after the surgical element has been deployedand retracted, the actuator is biased back to the initial position andthe apparatus is ready for repeat actuation. In another specificconfiguration, the actuator is moved along a longitudinal axis of motionwhich is parallel to the longitudinal axis of the push rod. In yetanother specific configuration, the actuator is two pivotal handles. Thehandles are movable between an initial outwardly separated position anda closed position in which the handles are adjacent to the body. A usersqueezes the handles to the closed position to move the surgical elementto the deployed position. In most configurations, the handles are biasedto the initial position, such that when the handles are released, thehandles return to the initial position and the incisor is ready forrepeat actuation.

[0007] In yet another embodiment, the incisor has an elongate rod with asurgical element disposed at the far end of the rod. A rod spring biasesthe rod and surgical element in the retracted position. A hammer ispositioned in the body, typically along an axis parallel with the pushrod. Actuation of an actuator engages an angled cam surface against thehammer to move the hammer to compress a hammer spring. Once the triggerand cam surface move past the hammer, the cam surface disengages fromthe hammer so that the hammer spring can expand and push the hammerdistally against the rod to move the surgical element to the deployedposition. Because the rod and surgical element are biased in theretracted position by the rod spring, the surgical element isinstantaneously pulled back to the retracted position.

[0008] In another aspect, the present invention provides methods offorming an incision in a tissue structure of a patient. In one method, aplunger is depressed substantially along a longitudinal axis of thedevice to move a surgical element from a retracted position to adeployed position. The surgical element is moved from the deployedposition to the retracted position independently of further movement ofthe plunger. In most embodiments, the plunger is biased back to anundepressed position such that the plunger is ready for repeatactuation.

[0009] In yet another method, the present invention provides a methodfor inserting a cannula into a blood vessel. The method comprisespositioning a tip of a device adjacent the blood vessel. An actuator isactivated to move a surgical element from a retracted position to adeployed position. The surgical element is automatically moved from thedeployed position to the retracted position while simultaneouslyinserting the cannula into the blood vessel. In most embodiments, theplunger is automatically returned to the undepressed position so thatthe plunger is ready for repeat actuation.

[0010] In yet another method, the present invention provides a method ofcreating an incision. The method comprises placing a distal tip of adevice adjacent a vessel wall. An actuator is activated to compress aspring. The spring is expanded to deploy a surgical element to create anincision in a vessel. Thereafter, the surgical element is automaticallyretracted.

[0011] In yet another method, the present invention provides a methodfor occluding an aorta. A surgical element is deployed to create anopening in the aorta. The surgical element is automatically retractedand the cannula is inserted through the opening and into the aorta. Thesurgical element is withdrawn from the cannula and an aortic occlusiondevice is positioned in at least a portion of the aorta. In somemethods, the aortic occlusion device includes an inflatable balloonwhich is expanded to occlude the aorta.

[0012] In still another aspect, the present invention provides anassembly for creating an incision in a blood vessel. The assemblyincludes a cannula having a lumen. An incisor having an automaticallyretracting surgical element is removably receivable within the lumen ofthe cannula. The cannula has a body and a push rod with a surgicalelement. An actuator is coupled to the push rod to move the surgicalelement between a retracted position and a deployed position. A fixedrelease mechanism is positioned within the body to disengage the pushrod from the actuator to allow the push rod and surgical element to bebiased from the deployed position to the retracted position.

[0013] In another embodiment, the assembly includes a cannula and anincisor having a hammer type assembly for retracting the surgicalelement. A hammer and hammer spring are positioned within the body andadjacent the push rod. A cam surface, typically coupled to an actuator,moves to compress the hammer and hammer spring. The cam surface is movedbeyond the hammer and allows the hammer spring to expand so as to pushthe hammer distally against a push rod. The impulse from the hammermoves the surgical element from a retracted position to a deployedposition. In most assemblies, the surgical element (and rod) are biasedto the retracted position, such that the surgical element is immediatelybiased back to the retracted position.

[0014] In another embodiment, the present invention provides an assemblyfor treating the ascending aorta. The assembly includes a cannula havinga lumen and an incisor having an automatically retracting surgicalelement. The incisor is removably received in the lumen of the cathetersuch that a surgical element is positioned near a distal end of thecannula to create an incision in the ascending aorta. An aorticocclusion device can be inserted through the lumen of the cannula andinto the incision in the ascending aorta after the incisor has beenremoved from the cannula.

[0015] Other aspects, features, and advantages of the present inventionwill become apparent upon consideration of the following detaileddescription and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a perspective view of an incisor within a cannula;

[0017]FIG. 2 shows the cannula;

[0018]FIG. 3 shows an enlarged view of the distal end of the cannula ofFIG. 2;

[0019]FIG. 4 is a plan view of a ring;

[0020]FIG. 5 is a side view of the ring of FIG. 4;

[0021]FIG. 6 show an aortic occluding device;

[0022]FIG. 7 shows the incisor disposed within the cannula and theincising element in a retracted position;

[0023]FIG. 8 shows the incisor disposed within the cannula and theincising element in a deployed position;

[0024]FIG. 9 shows the introduction of the cannula into the ascendingaorta;

[0025]FIG. 10 shows the aortic occlusion device and cannula passingthrough an incision in the ascending aorta;

[0026]FIG. 11 is an exemplary embodiment of the incisor;

[0027]FIG. 12 is a cross-sectional view of the structure of the incisorof FIG. 11 with the plunger in an undepressed position and the incisingelement in a retracted position;

[0028]FIG. 13 is a cross-sectional view of the structure of the incisorof FIG. 11 with the plunger in a partially depressed position and theincising element in a deployed position;

[0029]FIG. 14 is a cross-sectional view of the structure of the incisorof FIG. 11 with the plunger in a fully depressed position and theincising element in the retracted position;

[0030]FIG. 15 is a cross-sectional view of another exemplary embodimentof an incisor with handles in an extended position and the incisingelement in a retracted position;

[0031]FIG. 16 is a cross-sectional view of the incisor of FIG. 15 withthe handles in a closed position and the incising element in a deployedposition;

[0032]FIG. 17A shows yet another embodiment of the incisor;

[0033]FIG. 17B shows the embodiment of 17B with the thumb switch in aproximal position and the surgical element in a retracted position;

[0034]FIG. 17C shows the thumb switch moving distally and the surgicalelement in a deployed position;

[0035]FIG. 17D shows the thumb switch in a distal position and thesurgical element in the retracted position;

[0036]FIG. 18 shows a cross-sectional view of still another embodimentof the incisor of the present invention with the plunger in anundepressed position and the surgical element in a retracted position;

[0037]FIG. 19 shows a cross-sectional view of the incisor of FIG. 18with the plunger in a partially depressed position and the surgicalelement in a retracted position;

[0038]FIG. 20 shows a cross-sectional view of the incisor of FIG. 18with the plunger in a fully depressed position and the surgical elementin a deployed position; and

[0039] FIGS. 21A-21D illustrate a method of creating an incision in avessel.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

[0040] Apparatus and methods according to the present invention willgenerally be adapted for creating an incision within a target area of abody lumen, usually in the ascending artery or other coronary arteries.

[0041] In preferred embodiments, systems according to the presentinvention will comprise incisors, cannulas, and aortic occluding deviceshaving elongate bodies adapted for introduction into the body. Thedimensions and other physical characteristics of the catheter bodieswill vary significantly depending on the procedure performed. In anexemplary case, the cannula, incisor, and aortic occluding device bodiesare flexible to allow introduction from the outside the patient's cavityto the target site in the aorta or the heart. In other embodiments, anyor all of the devices may be partially or entirely rigid.

[0042] Cannula bodies will typically be composed of a bicompatibleorganic polymer which is fabricated by conventional extrusiontechniques. Suitable polymers can be found in commonly owned U.S. Pat.No. 5,863,366, the full disclosure of which is incorporated herein byreference. Optionally, at least a portion of the cannula housing may bereinforced with braid, helical wires, axial filaments, or the like, inorder to increase rotational strength, column strength, toughness,pushability, and the like. However, in some embodiments at least aportion of the lumen is not reinforced so that a clamp can be placedover the lumen to prevent the flow of body fluid (i.e. blood) up thelumen. A first arm of the cannula often has a keying feature, such as acolored marking, line, molded feature, or the like, which can promoteproper alignment of the incisor with the cannula and with the aorta. Inmost embodiments, the combined weight of the cannula and incisor will bevery light to facilitate easy manipulation and placement of theapparatus using one hand.

[0043] A surgical element, such as a cutting blade will be positioned atthe distal end of the incisor. The cutting blades usually have at leasttwo outwardly facing cutting edges and usually are formed from a metalsuch as stainless steel, but can also be formed from hard plastics,ceramics, or composites of two or more materials, which can be honed orotherwise formed into the desired cutting edge. In the exemplaryembodiments, the cutting blades have a width which is approximatelyequal to the inner diameter of the cannula. For example, when incisingthe ascending aorta, the blades will typically have a width betweenapproximately 4 mm and 6 mm. The larger blades have been found create aclean incision while minimizing tearing in the artery wall. In mostembodiments, the blade will extend approximately 2 mm-6 mm past thedistal tip of the incisor. Optionally, the cutting edges of the bladesmay be hardened, e.g. by chrome plating.

[0044] The incisor uses an actuator, plunger, trigger, or the like toactuate the deployment and retraction of the surgical element. In someembodiments, the trigger is movable along a parallel axis with thelongitudinal axis of the cannula and incisor. Users can better controlthe deployment and retraction of the incising element when the triggeractuation direction is in the same direction as the deployment of theblade and insertion of the cannula. However, the present invention isnot limited to such a configuration and in other embodiments alternativetrigger configurations can be used.

[0045] While the remaining discussion will be directed toward creatingan incision in the ascending aorta, it will be appreciated that theconcepts of the present invention can be used to create an incision orperforation in a variety of other organs, vessels, and tissuestructures.

[0046] Referring to FIG. 1, a system 10 of the present inventioncomprises a cannula 12 and an incisor 14. As illustrated in FIGS. 1 and2, the cannula 12 is typically used to return oxygenated blood to thepatient when the patient's heart is arrested. The cannula comprises alumen 16 having a proximal end 18 and a distal end 20. The lumen 16 hasa reinforced section 21. The reinforced section 21 is preferably formedin the manner described in U.S. Pat. No. 5,863,366, which was previouslyincorporated by reference. A Y-arm connector 22 having a first arm 24and a second arm 26 is fluidly coupled to the proximal end of theelongate lumen 16. The first arm 24 has an opening which can receive theshaft of the incisor 14. The second arm 26 has a hemostasis valve 27.The hemostasis valve 27 can be any of a variety of known hemostasisvalves, but is preferably a Thouy-Borst valve. Referring now to FIG. 3,the distal end 20 of the cannula is angled and has a distal opening 28and two side ports 30 for infusing oxygenated blood into the vasculatureof the patient. Optionally, radiopaque markers 32 are provided at thedistal end for visualization using fluoroscopy. As shown most clearly inFIGS. 4 and 5, a ring 34 is attached to the distal end 20 of the cannula12. The ring 34 limits the depth of insertion of the cannula 12 into thevessel, stabilizes the cannula 12, and receives pursestring sutureswithin slots 36 to provide hemostasis around the cannula 12 when thecannula 12 is positioned in the vessel.

[0047] The system of the present invention includes, in a preferredembodiment, an aortic occlusion device for internal occlusion of theaorta. Referring to FIG. 6, one embodiment of an aortic occlusion device13 is shown. The aortic occlusion device 13 has an occluding member 15configured to occlude a patient's ascending aorta. The occluding memberis preferably a balloon but may also be a mechanically actuated member.The aortic occlusion device 13 has an inflation lumen 17 for inflatingthe occluding member 15, a pressure lumen 19 for measuring pressure inthe ascending aorta, and a lumen 21 for delivering cardioplegic fluidand/or venting the ascending aorta. The aortic occlusion device 13 canbe manufactured in a manner such as extrusion, but is preferablymanufactured and used as described in U.S. patent application Ser. No.08/782,113, filed Jan. 13, 1997, the full disclosure which isincorporated herein by reference.

[0048] The aortic occlusion device 13 is preferably substantiallystraight in an unbiased position, however, the aortic occlusion devicemay also have a shaped end. For example, the aortic occlusion device canhave a curved or an L-shaped end which facilitates positioning theoccluding member 15 in the ascending aorta depending upon the surgicalapproach. The aortic occlusion device is preferably flexible so that itcan be bent as necessary without kinking. A more complete discussion ofthe aortic occlusion device can be found in U.S. patent application Ser.No. 09/235,043, filed Jan. 21, 1999, the full disclosure of which isincorporated herein by reference. In use, the aortic occlusion device 13can be introduced into the patient through the cannula 12. The cannulais positioned in a patient's ascending aorta with the aortic occlusiondevice 13 passing through the hemostasis valve 27 (FIG. 10).

[0049] Referring now to FIGS. 7-8, an introducing incisor 14 ispositioned in the cannula 12 to create an incision so that the cannula12 and aortic occlusion device 13 can be introduced into the vessel. Theincisor has a connector hub 38 which is received by the first arm 24 ofthe cannula 12 to provide a sealed connection between the incisor 14 andthe cannula 12. The incisor 14 has an incising element 40 to create anincision in the wall of the vessel. The incising element 40 is attachedto a push rod (not shown) which is coupled to a plunger 42 for movingthe incising element 40 between the retracted position (FIG. 7) and theexposed position (FIG. 8). The incising element 40 is preferably biasedin the retracted position and is only exposed when the plunger 42 isdepressed by the user.

[0050] Generally, purse string sutures 39 can be sewn in the ascendingaorta prior to advancing the cannula and incisor. The purse strings canprovide hemostasis around the cannula (after it has been advanced intothe aorta). The cannula and incisor are then moved adjacent an outerwall of the aorta. In some embodiments, the distal tip 56 of the incisor14 can include traction features 57, such as a roughened surface,protrusions, or the like, which help maintain the distal tip within thepurse string sutures (FIG. 11). Light pressure is applied to the incisorto create a dimple or indentation in the aorta so that the distal tipremains in a centered position within the purse strings when theincising element is advanced into aorta wall. After the incision iscreated, the cannula and incisor are advanced through the incision andinto the aorta. The incising element is retracted as the trigger isadvanced and the purse string sutures are tensioned around the cannula.The radiopaque marker at the cannula tip may be viewed under fluoroscopyand the cannula manipulated until the angled tip is directed toward theaortic valve (FIG. 9). The aortic occlusion device is then passedthrough the hemostasis valve and advanced until the occluding member ispositioned in the ascending aorta. Delivery of oxygenated blood,occlusion of the ascending aorta, and delivery of cardioplegic fluid isthen performed in the manner described in U.S. Pat. No. 5,584,803, thefull disclosure of which is incorporated herein by reference.

[0051] As shown in FIG. 10, the lumen 21 of the occlusion device iscoupled to a source of cardioplegic fluid 43, the inflation lumen 15 iscoupled to a source of inflation fluid 47, and the pressure lumen 19 iscoupled to the pressure monitor 51 for measuring pressure in theascending aorta. The lumen can also be coupled to a vacuum source 53 forventing the ascending aorta.

[0052] The first arm 24 of the cannula is coupled to a source ofoxygenated blood 55 so that blood is delivered through the lumen of thecannula with the blood passing through the annular region between thecannula 12 and the aortic occlusion device.

[0053]FIGS. 11 and 12 illustrate an exemplary embodiment of an incisorof the present invention. The incisor 14 includes a push rod 48 having aproximal end 50 and a distal end 52. The push rod is rigid enough totransmit a compressive force between the proximal and distal ends, butpreferably is still flexible enough to advance through a curved cannula.A surgical element 40 such as a blade or incising element is attached tothe distal end of the push rod 48, while the proximal end of the pushrod has a surface or enlarged push cap which can be engaged by at leastone plunger finger (described in more detail herein below). An elongatehousing 54 having a tapered or angled distal tip surrounds the push rodand incising element. An opening or slot within the angled distal tip 56allows the surgical element to move from a retracted position to adeployed position. A body 58 having an opening which receives theproximal end of the push rod 50 is attached to the proximal end of theelongate housing 54. A retraction spring 60 positioned within the body58 is coupled to the proximal end of the push rod 50 to bias the pushrod 48 and surgical element 40 in the retracted position. A movableactuator 42, such as a plunger or trigger, releasably engages theproximal surface of the push rod. As will be described in more detailbelow, a ramp or cam surface 70 is disposed within a distal end of thebody 58 to disengage the fingers 64 from the push rod as the plunger 42moves toward the fully depressed position. Optionally, a set screw 68can be attached to the plunger 42 to prevent the plunger 42 fromrotating. Additionally, the set screw 68 can act as an indicator toinform the user how far the incising element has been deployed.

[0054] As illustrated in FIG. 11, in some configurations the body hastwo finger grips 72 which extend radially from the body 58 and a plunger42 that extends proximally through an opening in the body 58. Theincisor is grasped with the user's fingers like a hypodermic needle andis actuated with either the thumb or the palm of the hand. Such aconfiguration allows the user to manipulate the incisor with only onehand, while providing the user with enhanced control of the incisor.

[0055] As shown in FIG. 12 the plunger is maintained in the undepressedposition by a plunger return spring 66, and the blade 40 is maintainedin the retracted position within the distal tip 56 by the rod retractionspring 60. In the initial undepressed position the plunger finger(s) 64may or may not contact the proximal end of the push rod 50. As shown bythe arrow in FIG. 13, the plunger is advanced by pushing on theengagement surface 62 to overcome the resistance of the return spring 66and retraction spring 60. Protrusions 63 on the plunger finger(s) 64contact and begin to push on the proximal surface 50 of the push rod. Asthe plunger 42 is advanced, the push rod 48 and surgical element 40 areadvanced with the plunger. In most embodiments the push rod 48 and blade40 are advanced at a 1:1 rate with the plunger 42, however, in otherembodiments, the ratio can be modified. As the plunger nears the end ofits path, a surface of the plunger finger(s) 64 engage the ramps 70. Asthe fingers advance over the ramps, the fingers 64 are urged radiallyoutward away from the proximal end of the push rod. When the push rod 48has been advanced to a fully deployed position, the ramp disengages theplunger finger(s) 64 from the proximal end of the push rod (FIG. 14).The retraction spring 60 then urges the push rod 48 (and surgicalelement 40) back to its initial, retracted position. In mostembodiments, the release of the push rod will create an audible click toinform the user that the surgical element has been retracted.

[0056] As the plunger is released, the return spring 66 biases theplunger 42 back to the initial undepressed position (FIG. 11). As theplunger fingers 64 pass by the proximal surface of the push rod 48, theresilient spring force contained in the flexed plunger fingers bias thefingers radially inward to the initial position and into engagement (ornear engagement) with the proximal end 50 of the push rod. At thisposition, the plunger and push rod are positioned for additional repeatactuation. Optionally, a locking mechanism may be provided to lock theplunger after a single actuation to prevent inadvertent repeatactuation.

[0057] FIGS. 15 to 16 illustrate another exemplary embodiment of theincisor 14A having an automatically retracting surgical element. Theincisor 14A has a push rod 74 with a proximal end 76 and a distal end78. An incising element 80 is attached to the distal end of the push rodand a return plate 82 is coupled to the proximal end of the push rod.Return plate 82 is movable distally and proximally relative to body 87.An aperture 84 in the return plate 82 is sized to releasably receive atrigger pin 86. In most configurations, the trigger pin 86 is biasedwith a compression spring 90 into the aperture 84 of the return plate82. In most embodiments, handles 88 are pivotally coupled to body 87 andare linked to return plate 82 through the trigger pin. A ramp or camsurface 92 is disposed on the body adjacent the return plate 82 so thatactuation of the handle 88 and trigger pin 86 move the return plate,push rod, and surgical element from the retracted position to thedeployed position.

[0058] In use, a user actuates the handle (or actuator) 88 to move thereturn plate 82, push rod 74 and incising element 80 distally, therebymoving trigger pin 86 up the ramp 92. As the trigger pin 86 moves up theramp 92, the trigger pin 86 begins to move out of the aperture 84 in thereturn plate 82. When the trigger pin 86 reaches the top of the ramp,the trigger pin is urged out of the aperture and disengages from thereturn plate 82. A return spring 94 then urges the return plate 82, pushrod 74, and surgical element 80 back to the retracted position. When theuser releases the handle 88, a trigger return spring 96 or anequivalent, urges the actuator and trigger pin back to its initialposition. Because the trigger pin 86 is biased toward the return plate82, the trigger pin is urged back into the aperture 84 and the device isready for actuation.

[0059] In a specific configuration, the actuator comprises two pivotalhandles 88A, 88B which are movable between an extended position in whichthe handles are outwardly separated and a closed position in which thehandles are adjacent the body. Handle springs 96 bias the handles in theextended position and automatically return the handles to the extendedposition after each actuation. When the handles are squeezed together,return plate 82 is advanced distally and the trigger pin 86 is moved upthe ramp, as described above.

[0060] As illustrated in FIGS. 17A to 17D, in another specificconfiguration of the incisor 14B, the trigger comprises a linearlyactuated thumb trigger 88C which moves along an axis which issubstantially parallel to the longitudinal axis of the blade rod.Actuation of the trigger in a distal direction moves the surgicalelement distally. The distal motion of the trigger has been found to bemore natural since the distal movement of the trigger coincides with thedistal advancement of the blade and the distal advancement of thecannula through the incision.

[0061] As shown in FIGS. 17A and 17B, the incisor 14B has a push rod 74with a proximal end 76 and a distal end 78. An surgical element 80 isattached to the distal end of the push rod and a return plate 82 iscoupled to the proximal end of the push rod. Return plate 82 is movabledistally and proximally relative to body 87. An aperture 84 in thereturn plate 82 is sized to releasably receive a pin 86. In mostconfigurations, the pin 86 is biased with a compression spring 90 intothe aperture 84 of the return plate 82. Thumb switch 88C is slidablyattached to body 87 and is coupled to return plate 82 through the pin86. As shown in FIG. 17C, a ramp or cam surface 92 is disposed on thebody adjacent the return plate 82 such that actuation of the thumbswitch 88 and trigger pin 86 move the return plate 82, push rod 74, andsurgical element 80 from the retracted position to the deployedposition. As the pin 86 nears its most distal point, the ramp engagesthe pin and the pin 86 begins to move out of the aperture 84 (FIG. 17C).When the pin 86 reaches the top of the ramp, the pin is urged completelyout of the aperture. The pin 86 disengages from the return plate 82 anda return spring 94 urges the return plate 82, push rod 74, and surgicalelement 80 back to the retracted position. When the user releases thethumb switch 88C, a return spring 96 or an equivalent, urges the thumbswitch 88C and pin back to their initial position. Because the pin 86 isbiased by spring 90 toward the return plate 82, the pin is urged backinto the aperture 84 and the incisor is ready for repeat actuation.

[0062] Referring now to FIGS. 18-20, yet another incisor 14C is shown.The incisor shown comprises a mechanism which instantaneously advancesand retracts the surgical element. The incisor 14C has a distal surgicalelement 98 coupled to a push rod 100. Similar to above, the surgicalelement 98 and the push rod 100 are biased by a push rod spring 102 in aretracted position within an elongate housing 104. A hammer 106 having aprotrusion 108 is movable within housing 104 along substantially thesame axis as the push rod 100, although unconnected with the push rod. Ahammer compression spring 110 is disposed proximal of the hammer withinhousing 104 to provide the mechanism for actuating the hammer. A trigger112 comprising a cam or ramp 114 is movable in a transverse directionrelative to hammer 106 and is urged outwardly by a trigger spring 116(FIG. 18). Angled surface 115 of the cam engages the protrusion 108 andforces the hammer 106 proximally against the compression spring 110(FIG. 19). As the trigger 112 is advanced further, the cam 114 advancespast the protrusion 108 and allows the hammer spring 110 to expand andforce the hammer 106 distally so as to strike the proximal end of pushrod 100. The impulse from the hammer 106 moves the push rod 100 and thesurgical element 98 (i.e., a blade) instantaneously from its retractedposition to a deployed position (FIG. 20). Because the push rod 100 andsurgical element 98 are spring loaded to the retracted position, thepush rod 100 and surgical element 98 are immediately urged from thedeployed position back to the retracted position. The stiffness ofsprings 102 and 110 are selected such that the force of hammer 106 issufficient to overcome the resistive force of spring 102 to drive rod100 distally.

[0063] Use of the cannula, incisor and aortic occlusion device will nowbe described with reference to FIGS. 21A-21D. The description below isapplicable to all the incisors 14, 14A, 14B, 14C described herein.Referring again to FIG. 9, before introduction of the cannula, a ribretractor 115 or other device can be used to form an opening in anintercostal space such as the fourth intercostal space. The openingthrough the intercostal space is used for access to perform a surgicalprocedure such as a valve repair or replacement or coronary bypassgraft. The opening also provides direct access to the ascending aortafor control of the ascending aorta and to place purse string sutures inthe aorta. The surgeon then places two purse-string sutures 39 aroundthe site. The ends of the purse-string sutures are passed throughtourniquet tubing which is used to tension the purse-string sutures. Thepurse string sutures are then passed through the slots 36 in the ring34.

[0064] An incision is also created in the first or second intercostalspace in which a trocar is positioned. The cannula 121 and incisorassembly 120 are then introduced through the trocar and advanced to thesurface of the aorta with the incisor 119 positioned in the lumen 118 ofthe cannula 121. As illustrated in FIG. 21A, the cannula/incisorassembly are then advanced into contact with the aorta at the site nowsurrounded by the purse-string sutures. A light pressure can be appliedwith the traction features 123 of the distal tip 122 against the aortato create dimples or indentations so as to help center the surgicalelement within the purse strings. The user then depresses the plunger tomove the push rod 126 and the incising element 124 to a deployedposition (FIG. 21B). As shown in FIGS. 21C and 21D, the incising elementcreates an incision in the wall of the vessel, and the incisor and thecannula tip are pushed through the wall until the ring contacts theadventitial surface of the vessel. As the trigger is further depressed,the incising element is automatically released and returns back to theretracted position. Once the cannula tip has been inserted into theblood vessel, the incisor can be removed and the aortic occluding devicecan be inserted through the hemostasis valve in the first am and downthe cannula (FIG. 10).

[0065] The systems and methods described above have been described inrelation to the ascending aorta for clarity of understanding. Thedevices and methods of the present invention may have application inother parts of the aorta or heart and in other vessels and organs of thebody. As changes and modifications will be obvious to those of skill inthe art, the scope of the invention is limited solely by the followingclaims.

What is claimed is:
 1. An apparatus for creating a vascular incisioncomprising: a body; a rod movable relative to the body and having aproximal end and a distal end; a surgical element disposed at the distalend of the rod, wherein the rod and surgical element are movable betweena retracted position and a deployed position, wherein the rod andsurgical element are biased in the retracted position; an actuatorcoupled to at least one finger which engages the proximal end of therod, wherein activation of the actuator advances the surgical elementfrom the retracted position to the deployed position; and a ramp on thebody to engage the finger as the rod and surgical element move to thedeployed position, wherein the ramp disengages the finger from theproximal end of the rod to allow the surgical element to move to theretracted position.
 2. The apparatus of claim 1 further comprising areturn spring, wherein the actuator is movable between an undepressedposition and a depressed position, wherein the return spring biases theactuator to the undepressed position.
 3. The apparatus of claim 2wherein the actuator defines a longitudinal axis and the rod defines alongitudinal axis, wherein the longitudinal axis of the actuator issubstantially aligned with the longitudinal axis of the rod.
 4. Theapparatus of claim 1 wherein the actuator is coupled to multiple fingerswhich engage the rod.
 5. The apparatus of claim 1 wherein the proximalend of the rod comprises an enlarged push rod cap.
 6. The apparatus ofclaim 5 wherein the finger comprises a protrusion which engages the pushrod cap.
 7. The apparatus of claim 1 wherein the actuator is adapted tobe engaged by a user's thumb or palm.
 8. The apparatus of claim 1wherein the body comprises finger grips adapted to be held by the user'sfingers.
 9. The apparatus of claim 1 wherein the finger disengages fromthe rod when the rod and surgical element have been advanced to a fullydeployed position.
 10. The apparatus of claim 1 wherein the finger isflexible and is resiliently biased radially inward towards the proximalend of the rod.
 11. The apparatus of claim 1 wherein the disengagementof the finger from the rod creates an audible click.
 12. The apparatusof claim 1 wherein the ramp forces the finger radially outward away fromthe proximal end of the rod.
 13. The apparatus of claim 1 wherein thesurgical element is a blade.
 14. The apparatus of claim 13 wherein theblade has a width between approximately 4 mm and 6 mm.
 15. The apparatusof claim 13 wherein a leading edge of the blade has two outwardly facingedges.
 16. The apparatus of claim 13 wherein the rod is advanced at a1:1 rate with the actuator.
 17. The apparatus of claim 1 furthercomprising an elongate housing which extends distally from the body toencase the rod and surgical element.
 18. The apparatus of claim 17wherein the elongate housing and rod are flexible.
 19. The apparatus ofclaim 17 wherein the elongate housing comprises a tapered distal tiphaving an opening to allow the surgical element to move between theretracted position and the deployed position.
 20. The apparatus of claim17 further comprising a cannula removably coupled to the elongatehousing, the rod extending through the cannula.
 21. The apparatus ofclaim 20 wherein the cannula comprises a keying element to align thecannula in a predetermined orientation relative to the surgical element.22. The apparatus of claim 21 wherein the combination of the body, rod,surgical element, actuator, ramp, and rod spring are lighter than thecannula.
 23. An automatically retracting incisor comprising: a housing;a push rod having a proximal end and a distal end, wherein the push rodis movable between a retracted position and a deployed position, thepush rod coupled to the housing and biased toward the retractedposition; a surgical element disposed at the distal end of the push rod;a trigger pin releasably engaging the proximal end of the push rod; anda ramp on the housing engaging the trigger pin, wherein movement of thetrigger pin moves the push rod and the surgical element from theretracted position towards the deployed position such that the triggerpin slides along the ramp, wherein the trigger pin reaches a top of theramp and the trigger pin disengages from the push rod to allow thesurgical element and push rod to return to the retracted position. 24.The automatically retracting incisor of claim 23 wherein the trigger pinis coupled to an actuator, wherein the actuator is movable between aninitial position and an actuated position.
 25. The automaticallyretracting incisor of claim 24 wherein the actuator comprises twohandles.
 26. The automatically retracting incisor of claim 25 whereinthe handles are pivotally coupled to the body.
 27. The automaticallyretracting incisor of claim 26 wherein the handles in the initialposition are outwardly separated from the body and the handles in theactuated position are adjacent to the body.
 28. The automaticallyretracting incisor of claim 27 wherein the handles in the actuatedposition move the surgical element to the deployed position.
 29. Theautomatically retracting incisor of claim 27 wherein the handles arebiased towards the initial position.
 30. The automatically retractingincisor of claim 24 wherein the push rod defines a longitudinal axis andthe actuator defines a longitudinal axis of motion, wherein thelongitudinal axis of motion of the actuator is parallel to thelongitudinal axis of the push rod.
 31. The automatically retractingincisor of claim 24 wherein the actuated position is distal of theinitial position.
 32. The automatically retracting incisor of claim 24wherein the actuator comprises a thumb switch sidably coupled to thebody.
 33. The automatically retracting incisor of claim 24 wherein theactuator is biased to the initial position.
 34. The automaticallyretracting incisor of claim 23 wherein the trigger pin is removablyreceived in an aperture in the push rod.
 35. The automaticallyretracting incisor of claim 34 wherein the trigger pin is biased intothe aperture and is urged out of the aperture by the ramp.
 36. Theautomatically retracting incisor of claim 23 wherein the surgicalelement is a blade.
 37. The automatically retracting incisor of claim 23wherein movement of the surgical element from the deployed position tothe retracted position makes an audible sound.
 38. The automaticallyretracting incisor of claim 23 wherein the push rod and surgical elementare encased by an elongate housing, the elongate housing being attachedto the body.
 39. An incisor comprising: a body; an elongate rod coupledto the body, the elongate rod comprising a proximal end and a distalend; a surgical element positioned at the distal end of the rod, whereinthe surgical element and rod are movable between a retracted positionand a deployed position, the rod and surgical element being biased tothe retracted position; a hammer positioned in the body; a hammer springin engagement with the hammer; an actuator coupled to a cam having asurface which engages the hammer, wherein movement of the actuator froman initial position to an actuated position moves the hammer to compressthe hammer spring, wherein the cam disengages from the hammer, to allowthe hammer spring to expand and push the hammer distally against thepush rod so as to move the surgical element to the deployed position.40. The incisor of claim 39 further comprising a actuator spring whichbiases the actuator in the initial position.
 41. The incisor of claim 39wherein the surgical element and rod are biased to the retractedposition by a rod spring, the rod spring immediately biasing thesurgical element and rod from the deployed position to the retractedposition.
 42. The incisor of claim 39 wherein the hammer is decoupledfrom the elongate rod.
 43. A method of deploying and retracting asurgical element, the method comprising: depressing a plungersubstantially along a longitudinal axis of the device to move thesurgical element from a retracted position to a deployed position; andmoving the surgical element from the deployed position to the retractedposition independently of further movement of the plunger.
 44. Themethod of claim 43 further comprising biasing the plunger to anundepressed position.
 45. The method of claim 43 comprising informingthe user that the surgical element has been retracted.
 46. The method ofclaim 45 wherein the informing step is carried out by making an audibleclick.
 47. The method of claim 43 further comprising positioning thesurgical element through a cannula.
 48. The method of claim 43 whereinan incision in the tissue structure is created during the depressingstep.
 49. The method of claim 48 comprising advancing a cannula throughthe incision before removing the surgical element from the incision. 50.The method of claim 49 wherein the plunger is depressed in the samedirection as the cannula is advanced.
 51. The method of claim 49 whereinthe depressing step and the advancing step are carried out substantiallysimultaneously.
 52. The method of claim 43 further comprising releasingthe plunger to move the plunger from a depressed position to anundepressed position.
 53. The method of claim 43 wherein the moving stepis carried out by disengaging the plunger from a rod attached to thesurgical element.
 54. The method of claim 43 wherein the surgicalelement is a blade.
 55. A method of inserting a cannula into a bloodvessel comprising: positioning an incisor adjacent the blood vessel;activating an actuator to move a surgical element from a retractedposition to a deployed position to create an incision in the bloodvessel wall; and automatically moving the surgical element from thedeployed position to the retracted position while simultaneouslyinserting the cannula into the blood vessel.
 56. The method of claim 55further comprising maintaining the position of the incisor within thecannula during the moving step.
 57. The method of claim 55 furthercomprising automatically returning the actuator to an initial position.58. The method of claim 55 wherein the actuator is coupled to thesurgical element through a rod, wherein the moving step is carried outby biasing the rod to the retracted position.
 59. The method of claim 55wherein the actuator is advanced distally to move the surgical elementto the retracted position.
 60. The method of claim 55 wherein thecannula is inserted in the same direction as the actuator is advanced.61. The method of claim 55 wherein the activating step is carried out bysqueezing two handles together.
 62. A method of creating an incisioncomprising: placing a distal tip of a device adjacent a vessel wall;activating an actuator to compress a spring; expanding the spring todeploy a surgical instrument to create an incision in the vessel wall;and automatically retracting the surgical element.
 63. The method ofclaim 62 wherein the expanding step is performed independently offurther activating of the actuator.
 64. The method of claim 62 whereinduring the activating step the actuator engages a protrusion on a hammerwith a cam surface.
 65. The method of claim 64 wherein the expandingstep is carried out by moving the cam surface beyond the protrusion onthe hammer such that the hammer is released and the spring moves thehammer to deploy the surgical element.
 66. The method of claim 62further comprising biasing the actuator to an initial position, whereinthe actuator in the initial position is ready for repeat actuation. 67.An assembly for creating an incision in a blood vessel, the assemblycomprising: a cannula having a lumen; an incisor having an automaticallyretracting surgical element, the incisor being removably receivablewithin the lumen of the cannula, the incisor comprising: a body; a pushrod coupled to the surgical element, the push rod and surgical elementbeing movable relative to the body between a retracted position and adeployed position, wherein the push rod and surgical element are biasedin the retracted position; an actuator coupled to the push rod, theactuator facilitates the movement of the push rod and surgical elementfrom the retracted position to the deployed position; a fixed releasemechanism positioned on the body, wherein movement of the actuator to afirst position moves the push rod and surgical element from theretracted position to the deployed position so as to create an incisionin the blood vessel, wherein activation of the actuator to a secondposition causes the fixed release mechanism to disengage the push rodfrom the actuator and allow the push rod and surgical element to bebiased back to the retracted position.
 68. The assembly of claim 67wherein the actuator is biased back to an initial position.
 69. Theassembly of claim 67 wherein the actuator comprises handles pivotallyconnected to the body, wherein the handles in the first position areoutwardly separated from the body and the handles in the second positionare adjacent to the body.
 70. The assembly of claim 67 wherein theincisor comprises finger grips adapted to be held by a user's fingers.71. The assembly of claim 67 wherein the actuator comprises a thumbswitch.
 72. The assembly of claim 67 wherein the actuator is coupled tothe push rod with at least one flexible finger.
 73. The assembly ofclaim 67 wherein a trigger pin on the actuator releasably engages anaperture on the proximal end of the push rod.
 74. An assembly forcreating an incision in a blood vessel, the assembly comprising: acannula having a lumen; an incisor having an automatically retractingsurgical element, the incisor being removably receivable within thelumen of the cannula, the incisor comprising: a body; a rod having thesurgical element at a distal end, wherein the surgical element and rodare movable between a retracted position and a deployed position, therod and surgical element being biased to the retracted position; ahammer coupled to the body; a hammer spring in engagement with thehammer; a movable cam having a surface which engages the hammer, whereinmovement of the cam surface from an initial position to an actuatedposition moves the hammer to compress the hammer spring, whereindisengagement of the cam surface from the hammer causes the hammerspring to expand and push the hammer distally against the rod to movethe surgical element to the deployed position.
 75. A method of occludingan aorta comprising: deploying a surgical element to create an openingin the aorta; automatically retracting the surgical element; insertingthe cannula through the opening and into the aorta; withdrawing thesurgical element from the cannula; and positioning an aortic occlusiondevice in at least a portion of the aorta.
 76. The method of claim 75wherein the retracting step and inserting step are performedsubstantially simultaneously.
 77. The method of claim 75 wherein thesurgical element is moved from the retracted position to the deployedposition through activation of an actuator.
 78. The method of claim 77wherein the retracting step is carried out independently of furtheractivation of the actuator.
 79. The method of claim 75 wherein thecannula is inserted into the aorta before removing the surgical elementfrom the incision.
 80. The method of claim 75 further comprisingexpanding an occluding member to occlude aorta.
 81. An assembly fortreating the ascending aorta comprising: a cannula having a lumen; anincisor having an automatically retracting surgical element, the incisorbeing removably received in the lumen of the cannula, wherein thesurgical element is positioned near a distal end of the cannula tocreate an incision in the ascending aorta; and an aortic occlusiondevice insertable through the lumen of the cannula and into the incisionin the ascending aorta after the incisor has been removed from thecannula.
 82. The assembly of claim 81 wherein the cannula and incisorare simultaneously inserted through the incision.
 83. The assembly ofclaim 82 wherein the aortic occlusion device comprises at least onelumen and an occluding member.
 84. The assembly of claim 83 wherein theoccluding member comprises a balloon.
 85. The assembly of claim 81wherein the surgical element is attached to a push rod, wherein anactuator facilitates movement of the push rod and surgical element froma retracted position and a deployed position.